水蕴草对Pb、Cd的富集及其耐性机制研究

发布时间：2018-06-15 11:29

本文选题：水蕴草 + Pb　；参考：《昆明理工大学》2015年硕士论文

【摘要】：中国工业化的迅猛发展在给人类带来生活改善的同时也带来了严重的重金属污染问题,其中有色金属冶炼产业所带来的高污染重金属问题尤为突出。有色冶炼废水中的重金属成分复杂且含量较高,据初步调查,有色冶炼废水中的Pb、Cd含量约为10-300mg/L,高浓度的重金属含量给企业的污染治理带来了严峻的考验。目前,有色金属冶炼废水的处理方法主要有中和法、硫化法、铁盐除砷法、吸附法、膜法等,但受经济条件和自身技术的限制,每种方法都有一定的局限性,植物修复技术以其经济适用、无二次污染的优势很快成为治理重金属的主流技术。因此寻找合适的植物是植物修复的关键问题,具有理论和实践的意义。本研究利用沉水植物—水蕴草来处理不同浓度的Pb、Cd污水,系统研究了水蕴草对Pb、Cd的富集及其耐性机制,为水蕴草应用于高浓度Pb、Cd有色冶炼废水的治理提供理论基础,并为水蕴草对Pb、Cd的耐性机制提供一定的科学依据和参考价值。通过前期研究,得到了以下主要研究成果：1.采用半静态试验方法,研究水蕴草在9天的水培试验中对不同浓度Pb(0、5,10,20,40,80,100,120mg/L)、Cd(0,0.5,1,5,10,20,40mg/L)的富集量并用原子吸收分光光度计测定水蕴草体内的Pb、Cd含量。结果表明,在9天的水培实验中,水蕴草对Pb的富集量达到最大值10355mg/g(DW),水蕴草对Cd的富集量达到最大值3015mg/g(DW),均达到了超富集植物对PB、Cd的临界含量标准(Pb 1 OOOmg/kg= 1 mg/g, Cd 1 OOmg/kg=0.1 mg/g),能够耐受较高浓度的Pb、Cd污染水体,可以用来处理较高浓度含Pb、Cd的有色冶炼废水。2.研究不同浓度Pb、Cd对水蕴草生化指标的影响,并用紫外可见分光光度计对生化指标进行测定。结果表明,水蕴草受到不同浓度Pb、Cd胁迫均导致体内叶绿素a、叶绿素b、类胡萝卜素含量减少,游离脯氨酸含量增加,丙二醛含量升高。这些指标都是水蕴草在受到Pb、Cd胁迫时所表现出的适应机制。3.用差速离心法研究Pb、Cd在水蕴草亚细胞中的分布,并用原子吸收分光光度计对Pb、Cd在水蕴草亚细胞的含量进行测定。结果表明,Pb在水蕴草体内的分布规律为细胞壁细胞器与膜可溶性部分,Cd在水蕴草体内的分布规律为细胞壁可溶性部分细胞器与膜,其中细胞壁是Pb、Cd的主要贮存部位。所以,细胞壁的固化作用可能是水蕴草对Pb、Cd的耐性机制之一。4用化学试剂逐步提取法分析Pb、Cd存在的化学形态,并用原子吸收分光光度计对Pb、Cd在水蕴草不同化学形态的含量进行测定。结果表明,Pb在水蕴草体内的分布规律为盐酸提取态醋酸提取态氯化钠提取态去离子水提取态乙醇提取态残渣态。Cd在水蕴草体内的分布规律为氯化钠提取态醋酸提取态水提取态乙醇提取态盐酸提取态残渣态。综上表明水蕴草体内的Pb主要以盐酸提取态、醋酸提取态和氯化钠提取态为主,Cd主要以氯化钠提取态、醋酸提取态和水提取态为主。5.对Pb、Cd在水蕴草细胞壁、细胞器及膜中的化学形态进行,并用原子吸收分光光计对Pb、Cd含量进行测定。结果表明,细胞壁中Pb的赋存形态主要以盐酸提取态和醋酸提取态为主,细胞器和膜中的Pb主要以氯化钠和醋酸提取态为主,而细胞壁、细胞器及膜中Cd的赋存形态主要以氯化钠和醋酸提取态为主。6.综上表明水蕴草主要通过将Pb与草酸盐和磷酸盐相结合,将Cd与蛋白质结合态或吸附态和磷酸盐相结合,从而将其束缚在细胞壁中,限制了Pb、Cd进入细胞内部,从而减轻了Pb、Cd对水蕴草的毒害,增强了水蕴草对Pb、Cd的耐性。此外,脯氨酸含量的升高也在一定程度上反映了水蕴草对Pb、Cd的抗逆性。
[Abstract]:The rapid development of China's industrialization has brought serious heavy metal pollution to human beings, while the heavy metal pollution caused by the non-ferrous metal smelting industry is particularly prominent. The heavy metals in the non-ferrous smelting wastewater are complex and high in content. According to the preliminary investigation, the Pb, Cd in the non-ferrous smelting wastewater The content of the heavy metal content of high concentration has brought a severe test to the pollution control of enterprises. At present, the treatment methods of non-ferrous metal smelting wastewater mainly include neutralization, vulcanization, iron salt removal, adsorption and membrane, but limited by economic conditions and self technology, each method has some limitations and plant repair is limited. With its economic application, the advantage of no two pollution has quickly become the mainstream technology of controlling heavy metals. Therefore, it is of theoretical and practical significance to find suitable plants for phytoremediation. This study uses submerged plants - water plants to treat different concentrations of Pb, Cd sewage, and systematically studies the enrichment of Pb and Cd. The set and its tolerance mechanism provide a theoretical basis for the treatment of high concentration Pb, Cd non-ferrous smelting wastewater, and provide a scientific basis and reference value for the tolerance mechanism of Pb and Cd. Through the previous study, the following main research results are obtained: 1. the semi static test method is used to study the water content of water in 9 days. The concentration of Pb (0,5,10,20,40,80100120mg/L) and Cd (0,0.5,1,5,10,20,40mg/L) with different concentrations and the content of Pb and Cd in the water content were measured by atomic absorption spectrophotometer in the culture experiment. The results showed that in the 9 day hydroponic experiment, the enrichment of Pb was reached the maximum value 10355mg/g (DW) in the 9 day hydroponics experiment, and the enrichment of Cd was reached the maximum. The value 3015mg/g (DW) has reached the critical content standard of PB, Cd (Pb 1 OOOmg/kg= 1 mg/g, Cd 1 OOmg/kg=0.1 mg/g), and can tolerate higher concentration Pb, and Cd polluted water can be used to deal with the high concentration of non-ferrous smelting wastewater. The results showed that the content of chlorophyll a, chlorophyll b, carotenoid content decreased, free proline content increased, and the content of malondialdehyde increased in different concentrations of Pb and Cd stress, all of which were the difference in the adaptation mechanism of.3. used by Pb and Cd stress. The rapid centrifugation was used to study the distribution of Pb and Cd in the subcellular of water accumulation, and the content of Pb and Cd was measured by atomic absorption spectrophotometer. The results showed that the distribution of Pb in the water content grass was the cell wall organelles and the soluble part of the membrane, and the distribution law of Cd in the water content grass body was the soluble part of the cell wall. The cell wall is the main storage site of Pb and Cd, so the curing effect of the cell wall may be one of the resistance mechanism of Pb, Cd,.4 using chemical reagent to analyze the chemical form of Pb, Cd, and determine the content of Pb in different chemical forms by atomic absorption spectrophotometer. The results showed that the distribution of Pb in the extracted state of hydrochloric acid was the extraction state of sodium chloride extracted state of hydrochloric acid from the extracted state of sodium chloride and the extracted state of deionized water in the extracted state of hydrochloric acid. The distribution of.Cd in the distilled state of the extracted state of ethanol in the water content of the extracted state of the extract state of the extracted state of sodium chloride was the extracted state of the extracted state of hydrochloric acid extracted state of the extracted state of acetic acid from the distilled state of acetic acid. The results showed that the Pb in the aqueous herb body was in a comprehensive way. The main use of hydrochloric acid extraction state, acetic acid extraction state and sodium chloride extraction state, Cd mainly with sodium chloride extraction state, acetic acid extraction state and water extraction state as the main.5. on Pb, Cd in the cell wall, organelles and membrane chemical morphology of Cd, and the determination of Pb and Cd content by atomic absorption spectrophotometer. The results show that the cell wall of Pb in the wall. The main forms are extraction state of hydrochloric acid and extraction state of acetic acid. The main Pb in organelles and membranes are sodium chloride and acetic acid, while the main forms of cell wall, organelles and membrane Cd are mainly sodium chloride and acetic acid extraction state as the main.6., which mainly through the combination of Pb with oxalate and phosphate, and Cd with Cd. Binding to the protein binding state or adsorbed state and phosphate, binding it to the cell wall, limiting the Pb and Cd into the cell, thus reducing the toxicity of Pb, Cd to the herb, and enhancing the tolerance to Pb and Cd. In addition, the increase of proline content also reflects the resistance to Pb and Cd in a certain degree.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173;X758

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